CODEWITHSUNDEEP
rdataframeinterpolation
B.Quaink
B.Quaink

Reputation: 586

Interpolate missing values of column based on values of another dataframe

I have two dataframes:

df1 <- data.frame(height = c(0, 100, 200, 300, 400), value = c(20, 30, 40, 50, 60))
df2 <- data.frame(height = c(40, 100, 200, 300, 500), value = c(NA, 35, 50, 60, 70))


df1                     df2
height  value           height  value
0       20              40      NA        
100     30              100     35           
200     40              200     50           
300     50              300     60           
400     60              500     70

Where I want to interpolate the values in df1 to fill in the missing height (40) in df2.

Upvotes: 1

Views: 158

Answers (1)

GKi
GKi

Reputation: 39737

You can use approxfun to Interpolate missing values of column based on values of another dataframe.

i <- is.na(df2$value)
df2$value[i] <- approxfun(df1$height,  df1$value)(df2$height[i])
df2
#  height value
#1     40    24
#2    100    35
#3    200    50
#4    300    60
#5    500    70

Upvotes: 1

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